1. Field of Invention
The present application is directed towards a system and method for simulating the evaporation of a droplet.
2. Description of the Related Art
Applying inkjet technology to the industrial printing process can greatly improve its efficiency. Inkjet technology can be used to save energy, material, money, and it can also help improve the environment. Inkjet technology may be used to manufacture of liquid crystal displays (LCD), thin film transistors (TFT), organic light emitting diodes (OLED), solar cells, micro-circuits, and other planar, layered, and 3-D structures. In the inkjet printing process, small droplets of a solution containing a solute with the desired properties and a solvent to make the solution jettable are deposited onto the target area. After the droplets reach the targeted area, the solvent evaporates and only the solute is left to form a final print pattern. The final pattern of the deposited solute directly determines the quality of the desired product.
In order to improve the quality of the final product, it is desirable to understand how the final pattern is formed in a realistic environment, what are the major factors affecting the final pattern, and how to control the production parameters in order to achieve a final product with the desired quality. In the final stage of ink drying process, the aspect ratio of length to height becomes quite large. Consequently, it is difficult to use traditional direct simulation methods to simulate the entire process. Lubrication equations may be applied to describe such phenomenon however in the prior art the use of lubrication type equations has been limited to flat surfaces.
A lubrication type concentration equation may also be used to describe the evolution of the concentration of solute in the droplet. This lubrication type concentration equation may describe the effect of fluid flowing inside the droplet and the effect of diffusion. The applicants have found that when the effect of diffusion is small relative to the effect of the flow of fluid, oscillations develop in the simulation that are not found in the physical system being simulated. The applicants have developed systems and methods for addressing this problem.
The present invention is directed towards addressing the problem of solving lubrication equations on a non-flat surface.